Default jpgs have very high NR at 1600 on the K3. Plus it's rather warm.

But obviously the FF will start being a bit better at high ISO. If it's FF you want, i'd wait a couple months, depending on lens you have or want. Ricoh has been quite fast to bring new products out, imho, and they have been talking about FF.

That said:

Your test will favour FF. Others will favour the fast and rugged aps-c.

Neither of the other 2 are weather sealed (if i am not mistaken).

Frame rate and buffer size are not at the same level. In fact, i don't think there is another 24mpx camera that can shoot anything close to 25 RAWs at 8.5 fps (give or take, and again, you've gotta check the specs).

With long lens, their reach is much less, or lens are much bigger and pricier.

C&N don't stabilize primes (except teles)...

They are quite different machines.

Oh, and C&N don't make limiteds (that's enough incentive for me not to look elsewhere for those focal lengths).